资源描述：
《N-杂环卡宾钯催化剂》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、2010年，MichaelG.Gardiner和他的同事合成了新型的氮杂环卡宾化合物，Acolorlesssolutionof1overanhydrousNa2CO3indryMeOHwasheatedat508Cfortwohourstogivearedsolution,fromwhichredcrystalsof2wereobtainedin84%yieldafterfiltrationandconcentration(Scheme1).[8]Complex2hashighstabilityasasolid(morethanoneyear)an
2、dinMeOHandTHF(severalmonths).Thecomplexistoleranttomoisture,butreactsquicklywithatmosphericoxygeninsolutionandthesolidstate.PeterD.W.Boyd,AlisonJ.Edwards,MichaelG.Gardiner,Angew.Chem.Int.Ed.2010,49,6315–6318.2008年，TakeshiMakino和他的同事得到了具有二齿氮杂环配体的钯配合物，ThebidentateNHC-palladiumco
3、mplexes4a–ewerepreparedbythereactionof1-(4-iodoaryl)-3-aryl-4,5-dihydroimidazoliniumsalt(1)[16]andxanthenediboronicacid(2)[17]inthepresenceofPd(PPh3)4andAg2Ofollowedbypalladation[18](Scheme1).Thebis(imidazolidene)derivative6wasalsosynthesizedinasimilarway(Scheme2).TakeshiMakin
4、o,HyumaMasu,KosukeKatagiri,RyuYamasaki,IsaoAzumaya,andShinichiSaito，Eur.J.Inorg.Chem.2008,4861–4865.TherearemanyexamplesofmonodentateNHCs,butonlyafewexamplesofalkane-bridgedchelatingbiscarbeneligands.Chelatedcarbenesareexpectedtobemorestablesinceonepossibledecompositionpathway
5、,reductiveeliminationofthecarbene,shouldbeslowerforthisconformationallyrestrictedcase.Achelatingcoordinationisonewaytoobtainhighlystablecatalystscapableoftoleratingharsherreactionconditionsthantraditionalphosphinecatalysts.SebastianAhrens和他的同事化合物长链烷烃桥联配体的钯配合物，SebastianAhrens,A
6、lexanderZeller,MariaTaige,andThomasStrassnerOrganometallics,Vol.25,No.22,2006N-Heterocycliccarbenes(NHCs),firstpreparedindependentlybyWanzlickandSchnherr[1]andfele[2]in1968,attractedlittleinterestfromthechemicalcommunityuntil1991,whenArduengoetal.revealedthefirststable,crystal
7、lineNHC(1,IAd).[3]Thepotentialofthisclassofcompoundstoserveasspectatorligandsintransition-metalcomplexeswasrecognizedin1995byHerrmannetal.[4]Soonthereafter,theexploitationoftheremarkablepotentialofNHCligandsincatalysisbegan.Theaboveseminalworksledtothedevelopmentofavarietyofot
8、herNHCplatforms(seerightcolumn)[5]andtheirtransition-metalcom
